Search PubMed⌕ Search

Biomedical subjects

J Hochberger

Publications and source records attributed to J Hochberger.

At least 55 records · Page 3Linked to original sources
PubMed1994

Coated and uncoated self-expanding metal stents for malignant stenosis in the upper GI tract: preliminary clinical experiences with Wallstents.

OBJECTIVES: The clinical feasibility of self-expanding metal stents with respect to the technical success, complications, and reintervention rate should be tested. METHODS: Five coated and 26 uncoated prototype Wallstents, especially designed for stenosis of the upper GI tract, were implanted in 23 patients. All patients with dysphagia suffered from inoperable tumor stenosis of the esophagus or the cardia. Stent implantation was performed under slight i.v. sedoanalgesia. RESULTS: Technical success was achieved in all 31 implanted stents. Forty-eight hr after implantation, dysphagia was improved in 21/23 patients. Acute problems observed within 1 wk were stent migration (1 patient, uncoated stent), oblique position of the stent (3 patients), epigastric or retrosternal pain (9 patients), insufficient stent expansion (4 patients), and pouch formation at the upper rim of the stent (4 patients). An uncomplicated follow-up (median 66 days, range 10-139 days) was seen in 12 patients (52%). Major problems in the follow-up period were stent migration in three patients (three coated stents, two stent migrations in one patient) and stent obstruction by tumor ingrowth/overgrowth and/or food impaction in eight patients (35%). Most of these problems could be successfully resolved by implantation of a second stent or electrocoagulation of overgrowing tumor tissue. By the 1st of March, 1994, three patients were still alive with a follow-up period of 530 days (median range, 336-880 days); 20 patients were decreased with a follow-up period of 70 days (median range, 3-374 days). CONCLUSIONS: Implantation of esophageal Wallstents is safe and has a low risk of acute complications and mortality for the patient. Early complications such as perforation and bleeding did not occur. Tumor ingrowth/overgrowth are the major reasons for the high reintervention rate in the follow-up period. Coated stents can resolve this problem, provided that stent migration can be avoided by improvement of the coating technology.

Adenocarcinoma↗
PubMed1993

New bougie applicator system for intraluminal "high dose rate" afterloading radiotherapy of esophageal carcinoma.

Applicators used to date in endoluminal "high dose rate" (HDR) afterloading (AL) radiotherapy of esophageal carcinoma consist of hollow plastic probes with an average thickness of 4 mm (1.8-5.0 mm), the diameter of which, however, often strongly deviates from that of the lumen of the tumor stenosis. Consequently, the probe can occupy an eccentric position in the esophagus. Exact dosimetry in the tumor region thus becomes virtually impossible, since the dose of the iridium emitter drops significantly with increasing distance (> 60% at a distance of 5 mm from the surface of the 4 mm probe). The bougie-type afterloading applicators developed by our group, however, offer a number of distinct advantages in comparison to conventional applicator probes: 1. Precise positioning of the applicator in the stenosis with simultaneous bougie effect. 2. Exact centering of the radiation source in the lumen of the esophagus. 3. Individual adaptation of the applicator size to the diameter of the residual lumen resulting from the tumor. 4. Upon patient-specific adaptation of the radiation exposure period, a distinct reduction of the surface (mucosa) dose is achieved together with simultaneous enhancement of the depth effect of radiotherapy treatment. Using these new afterloading bougies in over 150 treatment sessions involving 55 patients, no complications were thus far observed.

Brachytherapy↗
PubMed1993

[Laser lithotripsy in the treatment of bile duct calculi].

Currently more than 90% of all common bile duct stones can be removed non-surgically by means of endoscopic sphincterotomy, stone extraction and mechanical lithotripsy. For impacted, very large or very hard concrements intracorporeal shock wave lithotripsy by means of pulsed lasers represents a clinically newly established treatment procedure. Most clinical experience exists using the pulsed dye laser applied cholangioscopically via the endoscopic-retrograde or percutaneous-transhepatic route. The development of commercially available fine-caliber-endoscopes allows a relatively easy access to the stone compared to conventional mother-baby-scope-systems. A new stone-tissue-detection-system (STDS) in combination with a rhodamine-6G dye laser is promising for "blind" laser-lithotripsy using standard ERCP- or balloon catheters or a special lithotriptor basket. After successful conclusion of our in vitro and animal studies concerning the STD system we report on 18 patients with giant common bile duct stones using STDS in combination with a Rhodamin-6G dye laser.

Bile Ducts↗
PubMed1992

[Percutaneous and trans-papillary cholangioscopy: current diagnostic and therapeutic possibilities].

Peroral and transhepatic cholangioscopy represent a substantial enrichment of the diagnostic and therapeutic spectrum in gastroenterology. The use of cholangioscopy in the diagnostics of hepato-biliary disease seems to make especially sense in those cases where ERCP, sonography and CT do not lead to a sufficient clarification of the pathological findings and inspection, biopsy and cytology are required. An essential field of application for cholangioscopy consists today in the lithotripsy of giant common bile duct stones where laser lithotripsy means an important progress in the complication-free removal of these concrements. Percutaneous-transhepatic cholangioscopy as the more invasive procedure is especially indicated in those cases where due to former operations or special anatomical situations the endoscopic retrograde access is difficult or impossible. Further fields of application like endoluminal ultrasound via miniaturized probes or photodynamic diagnostics and photodynamic therapy (PDT) of cholangiocarcinoma seem to be valuable aims for the future.

Ampulla of Vater↗
PubMed1991

[Allergic enteropathy. Intestinally-mediated fungus allergy].

This article reports on a 53-year-old woman suffering from recurrent diarrhea since 1980 who, in November 1988, was admitted to the Medical Department of the University of Erlangen-Nuremberg with four to eight loose to liquid stools a day. Since January 1988, in addition to abdominal symptoms, including meteorism and recurrent abdominal pain, intermittent bouts of fever of up to 40 degrees C lasting six to eight hours and frequently occurring in the evening, had been noted. The patient's symptoms improved at weekends and during the holidays. Since 1977, she had been employed at a cheese counter, selling cheese. Noteworthy findings were an eosinophilia of 6% and, with the prick skin test, weakly positive reactions induced by two moulds with no increased total IgE and negative IgE RAST for diverse foods and moulds. An in vitro histamine-releasing test performed on colonic mucosal particles obtained at colonoscopy, a sensitization of the mucosa to moulds was demonstrated, and the patient was then given the mast cell stabilizing agent DNCG. This treatment cleared the symptoms, and she put on weight. In vitro tests on colonic biopsy material repeated in 1989 revealed a significant reduction in the release of histamine in response to the anti-allergic treatment.

Cladosporium↗
PubMed1991

Lithotripsy of gallstones by means of a quality-switched giant-pulse neodymium:yttrium-aluminum-garnet laser. Basic in vitro studies using a highly flexible fiber system.

The quality-switched neodymium:yttrium-aluminum-garnet laser represents a new instrument for athermal fragmentation of gallstones by transformation of optical energy into mechanical energy in the form of shock waves via local plasma formation. A highly flexible 300-micron fiber transmission system was used in basic investigations to determine the influence of varying pulse repetition rates (5-30 Hz) and pulse energies (15 and 20 mJ) on shock wave intensity and stone fragmentation in vitro for 105 biliary calculi of known size and chemical composition. After performance of 1200 shock wave pressure measurements using polyvinylidenefluoride hydrophones, stone fragmentation was analyzed by determination of fragment removal rates (volume of fragments removed per fragmentation time), ablation rates (mean volume removed per laser pulse), and median fragment sizes for each laser setting. With the quality-switched neodymium:yttrium-aluminum-garnet laser system, all concrements could be reliably disintegrated into small fragments (median diameter, 0.7-1.7 mm). Compared with pure cholesterol stones, a significantly higher fragment removal rate was achieved in cholesterol stones containing 30% calcium phosphate (P = 0.039), in cholesterol stones containing 20% pigment (P = 0.015), and in pure pigment stones (P = 0.007). Fragment removal rates, local shock wave pressures, and median grain sizes were significantly higher at a pulse energy of 20 mJ than with 15 mJ. Shock wave pressures showed a distinct dependence on pulse repetition rates at 20 mJ, yet not at 15 mJ. Because there is no evident hazard of thermal damage to tissue using the quality-switched neodymium:yttrium-aluminum-garnet laser, it appears to be a promising device for nonsurgical biliary stone therapy.

Aluminum↗
PubMed1991

[A new applicator for the intraluminal high-dose-rate irradiation of esophageal carcinoma].

Within the framework of multimodal treatment (radiation, chemotherapy) of esophageal carcinoma high dose rate intracavitary irradiation is used either as a boost or with a palliative intention. By use of a set of four tubes of different thickness (diameter 6, 8, 10, 14 mm) it is possible to adapt the diameter of the applicator to the remaining esophageal lumen. Thereby the radioactive source is placed centrally in the esophagus. The distance between the source and the mucosa is maximized and the radiation dose to the mucosa is reduced in comparison to a normal tube with a diameter of 4 to 6 mm. Better depth penetration of the dose can be achieved in deeper parts of the esophageal wall. The applicators are placed using a guide wire during endoscopy. If the malignant stenosis is endoscopically impassable, an intraluminal reduction of the tumours mass is performed by laser therapy or bougienage.

Brachytherapy↗
PubMed1988

Laserlithotripsy of common bile duct stones.

Endoscopic retrograde laser lithotripsy of common bile duct stones is a new technique which can be carried out through the endoscope without anaesthesia using ordinary endoscopic equipment. In the method described here a flashlamp pulsed Neodymium YAG laser (wave length 1064 nm) was used. Light energy was transmitted along a highly flexible quartz fibre with a diameter of 0.2 mm. This new technique was used in nine patients with concrements in the common bile duct, which could not be removed with the established endoscopic techniques. In eight of the nine the concrements (maximum diameter 4.7 x 3.1 cm) could be fragmented and in six the fragments could be extracted from the common bile duct. The total energy required was 80-300 J; complications were not observed.

Aged↗
PubMed1986

Laser-resistant guide probe for laser treatment of endoscopically impassable tumour stenoses.

A laser-resistant guide probe that can be placed endoscopically, for use in the laser treatment of impassable tumour stenosis is described. It meets the necessary requirements such as low level of absorption of YAG laser light (1,064 nm wavelength), high thermal stability and low heat conduction. So far, the probe has been used complication-free, in four patients.

Esophageal Stenosis↗
PubMed1986

Laser lithotripsy of gallstone by means of a pulsed neodymium-YAG laser--in vitro and animal experiments.

Using a flashlamp pulsed Nd: YAG laser it is possible to destroy gallstones within a few seconds (median: 4 sec for stones less than 1.5 cc; 9.5 sec greater than 1.5 cc). In in vitro and animal studies it was shown that the median energy needed for stone destruction varies between 32 Joule for stones less than 1.5 cc and 80 Joules for stones greater than 1.5 cc. A 0.2 mm thick, flexible glass fibre makes possible retrograde laser lithotripsy by conventional endoscopes. Using a suitable technique the danger of thermal damage to tissue is small.

Animals↗
PubMed1986

Laser-induced shockwave lithotripsy of gallstones.

With the aid of a Q-switched Nd:YAG laser with energy transmission via a flexible glass fiber, it proves possible under laboratory conditions, to destroy gallstones reliably and reproducibly. Lithotripsy is effected mechanically via a laser-induced local shockwave.

Cholelithiasis↗